This invention relates to a casing for housing small portable equipment such as portable terminal equipment, keyboards for cellular phones, cameras, remote controls, etc., and particularly to such casing adapted to have a strap attached thereto.
An example of the conventional small portable equipment casing of this type is disclosed in Japanese Patent No. 2548478 issued Oct. 30, 1996. The prior art casing will be briefly described with reference to FIGS. 1-3. The casing 10, which is of generally rectangular and low-profile construction, has its entire peripheral side wall vertically divided into two so as to define an upper casing half 11 and a lower casing half 12. The lower casing half 12 has protrusions 13 formed integrally with and extending from the bottom panel inboard at the four corners thereof while the upper casing half 11 are formed with protrusions 14 extending from the top panel inboard at the four corners thereof in opposing relation with the corresponding protrusions 13, as will be appreciated from FIG. 2 and FIG. 3 which is a cross-sectional view taken along the line 3xe2x80x943 in FIG. 1. A rectangular printed circuit board 15 having an electronic circuit mounted thereon is sandwiched between the four protrusions 13 and the opposed four protrusions 14. The printed circuit board 15 has small holes 16 formed therethrough at the four corners thereof. The protrusions 13 are each formed with through-bores 13a vertically aligned with and positioned below the corresponding small holes 16. The protrusions 14 have threaded holes (not shown) vertically aligned with and positioned above the corresponding small holes 16. Screws 17 are passed from outside of the bottom panel of the lower casing half 12 into and through the through-bores 13a and the small holes 16 and threaded into the threaded holes in the protrusions 14 to fasten the upper casing half 11, the lower casing half 12 and the printed circuit board 15 together. Mounted on the printed circuit board 15 is a liquid crystal display 18, the display window 19 for which is formed in the upper casing half 11.
A portion of the side wall of the lower casing half 12 at one corner of the casing 10 toward the printed circuit board 15 is cut out to form an opening 21. At the opening 21 the protrusion 13 has a reduced-diameter portion which is adapted to be fitted in and extend through a mating aperture 23 formed in one half section of a holder 22. The other half section of the holder 22 projects outside of the casing 10 and has formed therethrough a strap aperture 24. Further, the holder 22 has an integral complementary portion 25 in the middle thereof for closing the opening 21. It should be noted that when the casing 10 is assembled, the mating aperture 23 of the holder 22 is fitted over the protrusion 13 prior to the assembly of the casing. A strap 26 is attached to the holder 22 by being passed through the strap aperture 24.
It is to be appreciated that the construction of this conventional casing 10 requires no separate post dedicated for supporting the strap 26, since the strap 26 is attached to the protrusion 13 adapted for use to assemble the casing 10. However, there is a gap between the inner periphery of the through-bore 13a of the protrusion 13 and the outer periphery of the screw 17, so that a slightly strong tension applied to the strap 26 would be likely to break the portion of the protrusion 13 which is inserted in the mating aperture 23 of the holder 22.
The published microfilm of Japanese Utility Model Registration Application No. 57752/82 discloses another example of the conventional casing which is illustrated here in FIGS. 4 and 5. The casing comprises a rectangular box-like casing body 31 having an open end which is closed by a rear lid 32. The side wall of the casing body 31 at one or more of the corners thereof is recessed in the shape of a quater arc of circle to define a guide wall portion 33 within which is located a band mounting post 34 formed integrally with and protruding from the front panel of the casing body 31 toward the rear lid 32. A first shaft insertion bore 35 extends from the end face of the projecting end of the band mounting post 34 and through the post deep into the front panel of the casing body 31 for a distance longer than the length of the post 34. A second shaft insertion bore 36 is formed in the rear lid 32 in axially aligned and opposing relation with the first shaft insertion bore 35. A metal-made shaft 37 is inserted in the first and shaft insertion bores 35, 36 so as to substantialy fill the bores. A band 38 is attached to the casing by being passed around the band mounting post through a band insertion slot 39 defined between the guide wall portion 33 and the post 34.
In this example, the band mounting post 34 is reinforced by the shaft 37 so that there is little possibility of the band mounting post 34 being damaged under a relatively tight tension applied to the band 38. However, this construction required screws 30 for fastening the casing body 31 and the rear lid 32 together, which correspondingly increased the number of parts required for the construction, disadvantageously resulting in an increase in the number of steps of the manufacturing process.
According to this invention, an upper casing half and a lower casing half are superposed one on another to define a casing. A reentrant cavity is formed in one side wall of the casing. A strap supporting post is formed generally in the center of the reentrant cavity integrally with either one of the upper casing half and the lower casing half so as to extend form the one of the casing halves toward the other. The strap supporting post has a central screw bore extending from the end face of the projecting end thereof and therethrough deep into the root of the post. The other of the upper casing half and the lower casing half has a through-bore formed therethrough in opposing aligned relation with the end face of the strap supporting post so that a screw may be passed through the through-bore and threaded into the screw bore for the approximately entire length of the strap supporting post to fasten the upper casing half and the lower casing half together.